Large players:
Press L(2), C-Right, L(2), C-Right, L(2), C-Right, Z during game play. A message will appear at the bottom of the screen to confirm correct code entry.

Small players:
Press L(2), C-Left, L(2), C-Left, L(2), C-Left, Z. A message will appear at the bottom of the screen to confirm correct code entry. Repeat the code to make the players smaller than the basketball.

Full court dunks:
Press L(2), C-Down, L(2), C-Down, L(2), C-Down, Z. A message will appear at the bottom of the screen to confirm correct code entry. The player that entered the code may now dunk from any location on the court for the remainder of the quarter. However, you have to be ahead of the opponent's free throw to land a dunk.

Perfect shot:
Press L(2), C-Up, L(2), C-Up, L(2), C-Up, Z. A message will appear at the bottom of the screen to confirm correct code entry. The next shot from the player that enabled the code will always make it in the hoop.

Large ball:
Press L(2), C-Left, L(2), C-Up, L(2), C-Right, L(2), C-Down, Z. A message will appear at the bottom of the screen to confirm correct code entry. Repeat the code to disable its effect.

Faster running:
Begin game play in exhibition mode. Get possession of the ball and hold L + Z or R + Z while running to move faster.

Hidden courts:
Defeat all 29 teams in tournament play in Jam mode to unlock the Night and Beach courts.

if you cannot download trainer then go to Chrome/Firefox's settings, specifically to the Privacy settings and simply unchecking the "Enable phishing and malware protection" option.

Some Game Trainers are sometimes reported to be a Virus or Trojan,
the most common is a keylogger called HotKeysHook or the file
has been packed/protected with VMProtect or Themida and
is recognized as Win32/Packed.VMProtect or Win32/Packed.Themida.
In ALL cases this is a FALSE ALARM as NONE
of the Game Trainers @ GGMANIA contain known malicious code!!